Legitimate trolls selling items and buying trash

Riot really needs to start cracking down on players like this and I'm not talking a couple game ban here and there but rather to the extreme 50 game ranked bans, first offence, 2nd 100, 3rd time caught doing this should be permanent ranked bans. There is no reason for anyone to be trolling others that play ranked on a serious level literally causing people to drop tier upon tier.